Health Science News: Rewiring the Brain

Healing the nervous system’s fragile circuitry may require something more than mere drugs – like a shock to the system

By Robert Langreth

Lauri Sandoval tried more than a dozen drugs to treat a deep depression that darkened most of her adult life. None worked for long. Unable to hold a steady job, the 42 year old resident of New Mexico had to move in with her mother two years ago. Then she underwent surgery to implant an experimental device that treats her blues by transmitting tiny pulses of electricity to nerves in her neck.

Soon the mini shock therapy started to work. Today Lauri is back to working full time as personal assistant to a Hollywood star. “It’s incredible,” she says. “I am actually happy. I’ve never been able to say that before.”

The device that brought her back, made by the publicly held Cyberonics in Houston, Texas, is one of a new generation of pacemaker-style gadgets that use mild electrical jolts to treat myriad mental and neurological illness. While they aren’t cures, they may reduce or eliminate symptoms in severe cases, offering hope to millions of patients.

The brain uses electrical current to communicate within itself and with other parts of the body. When that fragile circuitry goes awry, it can play a role in disorders ranging from depression to epilepsy to Parkinson’s disease. Researchers are learning that precisely targeting barely noticeable pulses to affected areas of the brain can help restore some normal function to the cerebral circuitry.

Cyberonic’s poker-chip-size device, surgically implanted in the chest, is approved for treating drug-resistant epilepsy and has move into final-stage human tests for the far bigger market of drug-resistant depression. The medical device giant Medtronic is testing a related technique called deep brain stimulation, in which electrodes from a device in the chest are surgically threaded several centimeters into the brain to the site of damage. The method is approved in the U.S. for tremor and could win clearance for Parkinson’s disease later this year. A third method avoids surgery. At a doctor’s office, a patient wears a magnetic device on his head that generates gentle currents in parts of the brain hit by depression and schizophrenia.

Doctors have spent decades using drugs to tweak aberrant brain chemicals, with only limited success. For example, of 6 million Americans treated for depression, more than a million don’t respond to drugs. Of the 2.5 million epileptics in the U.S., about 10% can’t be helped by chemical therapy. Drugs for Parkinson’s disease often work initially, but their effectiveness fades.

Scientist have long thought that electricity might help, but until recently they have been unable precisely target particular regions of the brain. Electroshock therapy, the decades-old treatment of last resort for depression, indiscriminately blasts the entire head to induce seizures and jar patients out of their blues. While effective, it can cause severe short-term memory loss.

The techniques are better aimed with less collateral damage. Among the more promising ones are:

Electrical Healing
Brain stimulation is a relatively new way of treating severe mental and neurological illness with devices that deliver tiny pulses of electricity to the brain.

Deep-brain Stimulation
Medtronic’s Activa device is implanted in the chest like a pacemaker, with leads threaded deep into the brain during major surgery. It is approved for tremor, with approval expected soon for Parkinson’s disease.

Vagus Stimulation
Cyberonic’s nerve stimulator is similar, but wires are attached to he neck’s vagus nerve, a major conduit between the brain and other internal organs. It is approved for epilepsy and looks promising for depression.

Reference: Forbes Global